The present invention relates to a printer and, in particular, to a structure of a printer suited for POS/ECR applications and a method of controlling the same.
Conventional printers for printing on slips, which is one type of cut sheet, must generally have a flat recording sheet guide of large area because slips comes in various sizes and may contain many printing lines. Few such printers (generally called "slip printers") allow the use of a rolled sheet.
A validation sheet, which also is a type of cut sheet, is generally available in a regular size. However, validation sheets are multiple-layer sheets, that is, each validation sheet includes plural copying sheets behind the front or top sheet. Conventional printers dedicated to rolled sheet printing, on the other hand, have not been able to accommodate validation sheets along their recording sheet paths.
FIG. 13 shows a block diagram of a conventional record paper control system in which power is switchingly applied by a single drive source by switching the drive force using drive force switching means 501 between cut sheet printing and rolled sheet printing.
Recently, POS/ECR printers capable of handling various types of recording sheets used in POS markets have been called for.
However, in such integral printer, there are many technical problems hard to solve partly because the validation paper in general use consists of many sheets of paper to be copied; for example, some of the sheets may be torn or caught in a record paper passage when the passage is long, which gives rise to troubles.
Moreover, the conventional recording sheet forwarding paths, each driven by a separate drive source and a separate clutch, require an expensive and complicated control system involving a large number of parts. A single drive system employs a gear switching mechanism as the drive force switching means. However, to meet the latest demand not only for independent operation of both slip printing and rolled sheet printing but also for their simultaneous operation in which the slip printing content is simultaneously printed on a rolled sheet as a journal for security purposes (hereinafter referred to as "security slip"), the conventional printer does not provide the necessary functions.